SNAPCARD auth example

snapcard_auth_example.rb

require 'uri'
require 'net/http'
require 'digest/hmac'
require 'json'

class SnapcardApi
  MERCHANT_ID = 'ue5hsnusf8gene87asdf4es23bt9d7ak'
  API_KEY = '9idihi38o18mrm1234ipa1k9ooiifgts'
  SEC_KEY = '5e3kcoogptge6s5fh2qwertyb6g368dm'
  API_URL = 'https://api.snapcard.io'

  def create_invoice
    api_post('/invoices', {
      'currency' => 'USD',
      'lineItems' => [
        'itemName' => 'total',
        'quantity' => 1,
        'unitPrice' => 1.5
      ],
      'merchantId' => MERCHANT_ID
    })
  end

  private

  def api_post(path, post_data = {})
    params = {
      'timestamp' => (Time.now.to_i * 1000).to_s
    }

    url = API_URL + path + '?' + URI.encode_www_form(params)

    headers = {
      'X-Api-Key' => API_KEY,
      'X-Api-Signature' => calc_auth_sig_hash(url, post_data.to_json.to_s),
      'X-Api-Version' => '2'
    }

    uri = URI(API_URL)
    Net::HTTP.start(uri.host, uri.port, {:use_ssl => true}) do |http|
      http.request_post(url, post_data.to_json.to_s, headers) do |res|
        response = JSON.parse(res.body)
        raise response['message'] if res.code != '200'
        return response
      end
    end
  end

  def calc_auth_sig_hash(url, post_data_s = '')
    return Digest::HMAC.hexdigest(url + post_data_s, SEC_KEY, Digest::SHA256)
  end
end

api = SnapcardApi.new
puts api.create_invoice